Fire protecting device for air cooled engines



p 1938. J. w. DINTILH-AC 2,129,826

FIRE PROTECTING DEVICE FOR AIR COOLED ENGINES Filed Sept. 29, 1956 16am GEOYQES Dmtumc Inventor I LQWM Atkome s 1 Patented Sept. 13, 1938 UNITED STATES FIRE PROTECTING DEVICE FOR AIR 000mm ENGINES Jean'Georges Dintilhac, Paris, France plication September 29, 1936, Serial No. 103,198

In Belgium October 8, 1935 3 Claims. (Cl. 169-2) The present invention relates to air cooled internal combustion engines and it is more especially, although not exclusively, concerned with aircraft engines of the air cooled type having their cylinders disposed either in line or in radial manner.

The objectof the present invention is to provide an internal combustion engine of the kind above referred to which is devised for better protection against fire.

The essential feature of the present invention consists in combining, with engines of the type above referred to, a hood or fairing provided with air inlet apertures capable of being closed at will, and a fire extinguishing device disposed inside said hood, the whole being arranged in such manner that, in case of fire in the engine, the closing of said apertures permits of stopping the circulation of air inside the hood, and therefore of obtaining the maximum efficiency from the extinguishing device, since the fire tends already to be choked by the lack of oxygen.

Another feature of the present invention consists in fitting an engine of the type above referred to with a hood arranged in such manner as to divide the flow of cooling air into two distinct streams, one of which acts upon the cylinder bodies, being admitted through apertures provided at the front part of the hood and being adapted to be closed at will, whereas the other air stream cooperates, on the outer side,,with at least one part of the cylinder heads, this partitioning of the air circulation being obtained through the use of a sheet metal structure through which the cylinder bodies extend and devised in such manner that, when said apertures are fully closed, said sheet metal structure surrounds a chamber which is nearly wholly substracted to the action of the air of the surrounding atmosphere.

Still another feature of the present invention consists in the provision of means for automatically closing said apertures when the air extinguishingde'vice is brought into play.

Other features of thepresent invention will result from the following detailed description of a specific embodiment thereof.

A preferred embodiment. of the present invention will be hereinafter described, with reference to the accompanying drawing, given merely by way 'of example, and in which:

The only figure of said drawing shows, in diagrammatic sectional view, an airplane engine provided with a hood or fairing and a fire extinguishing device, the whole being made according to the present invention.

The example illustrated by the drawingrelates' more particularly to the case of an air cooled internal combustion engine foran aircraft, to be protected against fire.

adapted to be closed at will;

(a) On the one hand to a hood or fairing surrounding said engine, at least partly and provided with air inlet apertures adapted to be closed at will.

(b) On the other hand with a fire extinguishing device disposed on the inside of said hood close to the parts that are most exposed to danger of fire, that is to say, for instance, close to the carburetter, the fuel pipes and the fuel pumps.

The whole is arranged in such manner that the fire extinguishing device can act with the maximum efiiciency owing to the fact that, as soon as fire breaks, these apertures are closed, which .tends to create inside the hood a chamber in which air cannot penetrate, and in which, accordingly, fire tends to be quenched by the lackof oxygen.

Preferably, this arrangement is combined with the arrangement, applicable in particular to the case of radially arranged engines, according to which the hood or fairing is devised in such manner that it divides the circulation of cooling air into two distinct streams in the following manner: One of these streams acts on the bodies.

of the cylinders, either wholly or partly, this air stream being admitted through apertures provided at the front of the hood or fairing and on the other hand, the other air stream acts, on the outer side, upon at least a portion.. ofthe cylinder heads.

This partitioning is for instance obtained by means of a sheet metal structure through which extend the cylinder bodies close 'to the cylinder heads (eventually the lowepparts of the cylinder heads extend throughsaid metal partition when the whole of the cylind'er'heads is not to be subjected to the action of the second mentioned air stream). This sheet metal structure is such that it permits, when the apertures above mentioned are closed, of enclosing a chamber which is wholly, or nearly wholly, independent of the action of air from the surrounding atmosphere.

According to the present invention, considering first the hood proper, it may consist, for instance, in the case of. a radial engine, which will be more especially considered,. exclusively of a w the known manner, to guide the air for cooling the cylinder heads with the minimum of head resistance.

of course, according to the present invention, I may use any other arrangement for obtaining the desired result, that is to say for providing, around the crankcase I of the engine, a chamber I0 containing the bodies of the cylinders 8, carburetter 9 and the other fuel feed elements, this I ing means consist of a rotary shutter I5, adapted to be operated from a distance by the pilot.

The air that flows around the bodies of. the cylinders may be guided, if necessary, by defiect ing sheet metal plates of suitable shape and structure.

Of course, apertures or passages, eventually adjustable, are provided on the rear side of the cylinders, in such manner as to permit the out flow of the cooling air.

For instance, concerning the air stream that flows through chamber II], this air stream may flow through apertures l2 provided in the rear part of metal sheet element 3, in the case of the latter being joined to the fuselage.

Alternately, the air stream that has flown through annular chamber III may escape through the annular space left between 3 and the fuselage, when such an annular space exists.

The air stream II may itself. be evacuated through the annular space I3 existing between the fuselage and ring 6, when such a ring exists,

this space I3 being eventually adjustable by means of shutters such as I4.

Concerning now the fire extinguishing device, it is made for instance in the following manner:

I provide, at a suitable place of the hood or of the cockpit of the airplane, a reservoir of extinguishing fluid.

In order to feed this fluid to the places that are most exposed to the danger of fire, I provide feed jets or nozzles suchas l6, located for instance close to the carburetter.

Finally, a cock (or a link system) located within reach of the pilot controls the feed of said fluid under pressure. This cock may be adapted to be automatically operated by a device responsive to a rise of temperature.

Advantageously, in order to further increase 7 the safety, this cock may be arranged in such manner that it is interconnected with the link system that serves to operate shutter I5 so that the latter is automatically brought into the closed position when the cock is opened in consequence of a fire having broken inside the hood.

Whatever be the embodiment that is chosen, I obtain a system the operation of which is believed to result very clearly from the above description, and which has, over internal combustion engines of the kind with which the invention is concerned. many advantages among which the following may be cited:

Safety and protection against fire are greatly improved since, by closing shutter I5, the circulation of air through the space in which fire starts is stopped, and, even, the movement of the airplane tends to create in said space, through apertures and passages I2 and I3, a certain vacuum which facilitates extinguishing by lack of oxygen.

The system gives, at the same time, all the advantages of hoods or fairings ensuring 'an intensive cooling of the cylinder heads and a more moderate cooling of the cylinder bodies.

Finally, the system improves the homogeneity of the cooling action owing to the fact that the sheet metal partition tends to eliminate eddies on the inside of the hood. v

Of course, although the invention has been described as more specifically applied to the case of radial engines, it can be applied with the same advantage to the case of engines having their cylinders arranged in line.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiments of the present invention, it should be well understood that I do not wish to be limited thereto as there might be changes made in the arrangement, disposition and form of the parts without departing from the principle of the present invention as comprehended Within the scope of the appended claims.

What I claim is:

1. In combination, an internal combustion engine having a plurality of cylinders, a hood surrounding at least a part of said cylinders, provided with apertureslocated opposite at least a portion of said cylinders, for the inflow of cooling air from the atmosphere onto said cylinders, means for closing said apertures, a carburetor for said engine arranged within the hood, means at the rear of said hood to permit the escape of air therefrom and to create a low pressure so as to draw air from within said hood when said apertures are closed, and fire extinguishing means within said hood.

2. In combination, an internal combustion engine having a plurality of cylinders, a hood surrounding the cylinder bodies so that the cylinder heads project outwardly therefrom, said hood being provided with apertures located opposite at least a portion of said cylinders, for the infiow of cooling air from the atmosphere onto said cylinder bodies, means for closing said apertures, a carburetor for said engine arranged within the hood, means at the rear of said hood to permit the escape of air therefrom and to create a low pressure so as to draw air from within said hood when said apertures are closed, and fire extinguishing means within said hood.

3. In combination, an internal combustion engine having a plurality of cylinders, a hood surrounding the whole of said cylinders, a partition dividing the inside of said hood into two chambers one of which contains the bodies of the cylinders and the other the cylinder heads, said hood being provided, in its front part, with apertures located opposite at least a portion of said bodies of the cylinders and said cylinder heads, for the inflow of cooling air from the atmosphere onto said cylinders, means for closing at least the apertures opening into the first'mentioned chamber, said first chamber having an opening in its rear portion into said second chamber at a point where the pressure therein is reduced so as to draw air from said first chamber when the apertures in the front thereof are closed, a carburetor for said engine arranged within the hood, and fire extinguishing means within said hood.

JEAN GEORGES DIN'IILHAC. 

